Vox is a little and simple music player for Mac OS X with support for many file types, including FLAC, MP3, AAC, Musepack, Monkey's Audio, OGG Vorbis, Apple Lossless, AIFF, WAV, IT, MOD, XM, Games Music and many others. Includes numerous effects like Equalizer, Reverb, Time Stretch, Pitch Shift, Echo. Moreover, all supported files can be exported to AAC+, Apple Lossless, WAV and other formats with enabled effects.

Been using this for a few days as I don't have my external hard-drive with full iTunes library plugged in. I love it! Sure, they could add playlists and a bunch of other features, but I don't think I'd like it as much. It's small, fast and hasn't crashed or stuttered once. I donated via their website.

Handy player for those files you want to listen to before you add them to iTunes.
And it's also an excellent (and fast!) audio formats converter. The latest versions include LAME to convert to MP3.
Very nice interface too.
ToolPlayer is getting better and better with every new version.